The present invention relates to reactive ion etching (RIE), and more specifically, to using a near-amorphous zinc oxide mask when performing RIE.
RIE is an etching technology used in microfabrication. Unlike wet etching, RIE uses chemically reactive plasma to remove material deposited on wafers. The plasma is generated in low pressure (vacuum) by an electromagnetic field. High-energy ions from the plasma attack the wafer surface and react with it, thereby removing the material.
To pattern the material, RIE masks are used to cover portions of the surface that are not to be etched. The RIE masks are generally not affected by the high-energy ions, and thus, protect the underlying wafer from being etched. In this manner, RIE only etches a selected portion of the surface. Suitable RIE mask material includes metals such as aluminum, chromium, and titanium.